questionnaire-constraint.xml
   1 <?xml version="1.0" encoding="utf-8"?>
   2 <StructureDefinition xmlns="http://hl7.org/fhir">
   3   <id value="questionnaire-constraint" />
   4   <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
   5     <valueCode value="fhir" />
   6   </extension>
   7   <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
   8     <valueInteger value="1" />
   9   </extension>
  10   <url value="http://hl7.org/fhir/StructureDefinition/questionnaire-constraint" />
  11   <version value="4.0.1" />
  12   <name value="constraint" />
  13   <status value="draft" />
  14   <date value="2013-07-04" />
  15   <publisher value="HL7" />
  16   <contact>
  17     <telecom>
  18       <system value="url" />
  19       <value value="http://www.hl7.org" />
  20     </telecom>
  21   </contact>
  22   <description value="An invariant that must be satisfied before responses to the questionnaire can be considered "complete"." />
  23   <fhirVersion value="4.0.1" />
  24   <mapping>
  25     <identity value="rim" />
  26     <uri value="http://hl7.org/v3" />
  27     <name value="RIM Mapping" />
  28   </mapping>
  29   <kind value="complex-type" />
  30   <abstract value="false" />
  31   <context>
  32     <type value="element" />
  33     <expression value="Questionnaire" />
  34   </context>
  35   <context>
  36     <type value="element" />
  37     <expression value="Questionnaire.item" />
  38   </context>
  39   <context>
  40     <type value="element" />
  41     <expression value="Questionnaire.item.item" />
  42   </context>
  43   <type value="Extension" />
  44   <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  45   <derivation value="constraint" />
  46   <snapshot>
  47     <element id="Extension">
  48       <path value="Extension" />
  49       <short value="Constraint" />
  50       <definition value="An invariant that must be satisfied before responses to the questionnaire can be considered "complete"." />
  51       <comment value="This maps to the ElementDefinition.constraint element." />
  52       <min value="0" />
  53       <max value="*" />
  54       <base>
  55         <path value="Extension" />
  56         <min value="0" />
  57         <max value="*" />
  58       </base>
  59       <condition value="ele-1" />
  60       <constraint>
  61         <key value="ele-1" />
  62         <severity value="error" />
  63         <human value="All FHIR elements must have a @value or children" />
  64         <expression value="hasValue() or (children().count() > id.count())" />
  65         <xpath value="@value|f:*|h:div" />
  66         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
  67       </constraint>
  68       <constraint>
  69         <key value="ext-1" />
  70         <severity value="error" />
  71         <human value="Must have either extensions or value[x], not both" />
  72         <expression value="extension.exists() != value.exists()" />
  73         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])" />
  74         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
  75       </constraint>
  76       <isModifier value="false" />
  77     </element>
  78     <element id="Extension.id">
  79       <path value="Extension.id" />
  80       <representation value="xmlAttr" />
  81       <short value="Unique id for inter-element referencing" />
  82       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
  83       <min value="0" />
  84       <max value="1" />
  85       <base>
  86         <path value="Element.id" />
  87         <min value="0" />
  88         <max value="1" />
  89       </base>
  90       <type>
  91         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
  92           <valueUrl value="string" />
  93         </extension>
  94         <code value="http://hl7.org/fhirpath/System.String" />
  95       </type>
  96       <isModifier value="false" />
  97       <isSummary value="false" />
  98       <mapping>
  99         <identity value="rim" />
 100         <map value="n/a" />
 101       </mapping>
 102     </element>
 103     <element id="Extension.extension">
 104       <path value="Extension.extension" />
 105       <slicing>
 106         <discriminator>
 107           <type value="value" />
 108           <path value="url" />
 109         </discriminator>
 110         <description value="Extensions are always sliced by (at least) url" />
 111         <rules value="open" />
 112       </slicing>
 113       <short value="Additional content defined by implementations" />
 114       <definition value="May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension." />
 115       <comment value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone." />
 116       <alias value="extensions" />
 117       <alias value="user content" />
 118       <min value="0" />
 119       <max value="*" />
 120       <base>
 121         <path value="Element.extension" />
 122         <min value="0" />
 123         <max value="*" />
 124       </base>
 125       <type>
 126         <code value="Extension" />
 127       </type>
 128       <constraint>
 129         <key value="ele-1" />
 130         <severity value="error" />
 131         <human value="All FHIR elements must have a @value or children" />
 132         <expression value="hasValue() or (children().count() > id.count())" />
 133         <xpath value="@value|f:*|h:div" />
 134         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 135       </constraint>
 136       <constraint>
 137         <key value="ext-1" />
 138         <severity value="error" />
 139         <human value="Must have either extensions or value[x], not both" />
 140         <expression value="extension.exists() != value.exists()" />
 141         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 142         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 143       </constraint>
 144       <isModifier value="false" />
 145       <isSummary value="false" />
 146       <mapping>
 147         <identity value="rim" />
 148         <map value="n/a" />
 149       </mapping>
 150     </element>
 151     <element id="Extension.extension:key">
 152       <path value="Extension.extension" />
 153       <sliceName value="key" />
 154       <short value="Unique identifier" />
 155       <definition value="Unique id for the constraint within the questionnaire." />
 156       <min value="1" />
 157       <max value="1" />
 158       <base>
 159         <path value="Element.extension" />
 160         <min value="0" />
 161         <max value="*" />
 162       </base>
 163       <type>
 164         <code value="Extension" />
 165       </type>
 166       <constraint>
 167         <key value="ele-1" />
 168         <severity value="error" />
 169         <human value="All FHIR elements must have a @value or children" />
 170         <expression value="hasValue() or (children().count() > id.count())" />
 171         <xpath value="@value|f:*|h:div" />
 172         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 173       </constraint>
 174       <constraint>
 175         <key value="ext-1" />
 176         <severity value="error" />
 177         <human value="Must have either extensions or value[x], not both" />
 178         <expression value="extension.exists() != value.exists()" />
 179         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 180         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 181       </constraint>
 182       <isModifier value="false" />
 183       <isSummary value="false" />
 184     </element>
 185     <element id="Extension.extension:key.id">
 186       <path value="Extension.extension.id" />
 187       <representation value="xmlAttr" />
 188       <short value="Unique id for inter-element referencing" />
 189       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 190       <min value="0" />
 191       <max value="1" />
 192       <base>
 193         <path value="Element.id" />
 194         <min value="0" />
 195         <max value="1" />
 196       </base>
 197       <type>
 198         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 199           <valueUrl value="string" />
 200         </extension>
 201         <code value="http://hl7.org/fhirpath/System.String" />
 202       </type>
 203       <isModifier value="false" />
 204       <isSummary value="false" />
 205       <mapping>
 206         <identity value="rim" />
 207         <map value="n/a" />
 208       </mapping>
 209     </element>
 210     <element id="Extension.extension:key.extension">
 211       <path value="Extension.extension.extension" />
 212       <slicing>
 213         <discriminator>
 214           <type value="value" />
 215           <path value="url" />
 216         </discriminator>
 217         <description value="Extensions are always sliced by (at least) url" />
 218         <rules value="open" />
 219       </slicing>
 220       <short value="Extension" />
 221       <definition value="An Extension" />
 222       <min value="0" />
 223       <max value="0" />
 224       <base>
 225         <path value="Element.extension" />
 226         <min value="0" />
 227         <max value="*" />
 228       </base>
 229       <type>
 230         <code value="Extension" />
 231       </type>
 232       <constraint>
 233         <key value="ele-1" />
 234         <severity value="error" />
 235         <human value="All FHIR elements must have a @value or children" />
 236         <expression value="hasValue() or (children().count() > id.count())" />
 237         <xpath value="@value|f:*|h:div" />
 238         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 239       </constraint>
 240       <constraint>
 241         <key value="ext-1" />
 242         <severity value="error" />
 243         <human value="Must have either extensions or value[x], not both" />
 244         <expression value="extension.exists() != value.exists()" />
 245         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 246         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 247       </constraint>
 248       <isModifier value="false" />
 249       <isSummary value="false" />
 250     </element>
 251     <element id="Extension.extension:key.url">
 252       <path value="Extension.extension.url" />
 253       <representation value="xmlAttr" />
 254       <short value="identifies the meaning of the extension" />
 255       <definition value="Source of the definition for the extension code - a logical name or a URL." />
 256       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
 257       <min value="1" />
 258       <max value="1" />
 259       <base>
 260         <path value="Extension.url" />
 261         <min value="1" />
 262         <max value="1" />
 263       </base>
 264       <type>
 265         <code value="uri" />
 266       </type>
 267       <fixedUri value="key" />
 268       <isModifier value="false" />
 269       <isSummary value="false" />
 270       <mapping>
 271         <identity value="rim" />
 272         <map value="N/A" />
 273       </mapping>
 274     </element>
 275     <element id="Extension.extension:key.value[x]">
 276       <path value="Extension.extension.value[x]" />
 277       <short value="Value of extension" />
 278       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
 279       <min value="1" />
 280       <max value="1" />
 281       <base>
 282         <path value="Extension.value[x]" />
 283         <min value="0" />
 284         <max value="1" />
 285       </base>
 286       <type>
 287         <code value="id" />
 288       </type>
 289       <constraint>
 290         <key value="ele-1" />
 291         <severity value="error" />
 292         <human value="All FHIR elements must have a @value or children" />
 293         <expression value="hasValue() or (children().count() > id.count())" />
 294         <xpath value="@value|f:*|h:div" />
 295         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 296       </constraint>
 297       <isModifier value="false" />
 298       <isSummary value="false" />
 299       <mapping>
 300         <identity value="rim" />
 301         <map value="N/A" />
 302       </mapping>
 303     </element>
 304     <element id="Extension.extension:requirements">
 305       <path value="Extension.extension" />
 306       <sliceName value="requirements" />
 307       <short value="Why needed" />
 308       <definition value="An explanation of why this extension is required (for documentation purposes)." />
 309       <min value="0" />
 310       <max value="1" />
 311       <base>
 312         <path value="Element.extension" />
 313         <min value="0" />
 314         <max value="*" />
 315       </base>
 316       <type>
 317         <code value="Extension" />
 318       </type>
 319       <constraint>
 320         <key value="ele-1" />
 321         <severity value="error" />
 322         <human value="All FHIR elements must have a @value or children" />
 323         <expression value="hasValue() or (children().count() > id.count())" />
 324         <xpath value="@value|f:*|h:div" />
 325         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 326       </constraint>
 327       <constraint>
 328         <key value="ext-1" />
 329         <severity value="error" />
 330         <human value="Must have either extensions or value[x], not both" />
 331         <expression value="extension.exists() != value.exists()" />
 332         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 333         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 334       </constraint>
 335       <isModifier value="false" />
 336       <isSummary value="false" />
 337     </element>
 338     <element id="Extension.extension:requirements.id">
 339       <path value="Extension.extension.id" />
 340       <representation value="xmlAttr" />
 341       <short value="Unique id for inter-element referencing" />
 342       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 343       <min value="0" />
 344       <max value="1" />
 345       <base>
 346         <path value="Element.id" />
 347         <min value="0" />
 348         <max value="1" />
 349       </base>
 350       <type>
 351         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 352           <valueUrl value="string" />
 353         </extension>
 354         <code value="http://hl7.org/fhirpath/System.String" />
 355       </type>
 356       <isModifier value="false" />
 357       <isSummary value="false" />
 358       <mapping>
 359         <identity value="rim" />
 360         <map value="n/a" />
 361       </mapping>
 362     </element>
 363     <element id="Extension.extension:requirements.extension">
 364       <path value="Extension.extension.extension" />
 365       <slicing>
 366         <discriminator>
 367           <type value="value" />
 368           <path value="url" />
 369         </discriminator>
 370         <description value="Extensions are always sliced by (at least) url" />
 371         <rules value="open" />
 372       </slicing>
 373       <short value="Extension" />
 374       <definition value="An Extension" />
 375       <min value="0" />
 376       <max value="0" />
 377       <base>
 378         <path value="Element.extension" />
 379         <min value="0" />
 380         <max value="*" />
 381       </base>
 382       <type>
 383         <code value="Extension" />
 384       </type>
 385       <constraint>
 386         <key value="ele-1" />
 387         <severity value="error" />
 388         <human value="All FHIR elements must have a @value or children" />
 389         <expression value="hasValue() or (children().count() > id.count())" />
 390         <xpath value="@value|f:*|h:div" />
 391         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 392       </constraint>
 393       <constraint>
 394         <key value="ext-1" />
 395         <severity value="error" />
 396         <human value="Must have either extensions or value[x], not both" />
 397         <expression value="extension.exists() != value.exists()" />
 398         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 399         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 400       </constraint>
 401       <isModifier value="false" />
 402       <isSummary value="false" />
 403     </element>
 404     <element id="Extension.extension:requirements.url">
 405       <path value="Extension.extension.url" />
 406       <representation value="xmlAttr" />
 407       <short value="identifies the meaning of the extension" />
 408       <definition value="Source of the definition for the extension code - a logical name or a URL." />
 409       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
 410       <min value="1" />
 411       <max value="1" />
 412       <base>
 413         <path value="Extension.url" />
 414         <min value="1" />
 415         <max value="1" />
 416       </base>
 417       <type>
 418         <code value="uri" />
 419       </type>
 420       <fixedUri value="requirements" />
 421       <isModifier value="false" />
 422       <isSummary value="false" />
 423       <mapping>
 424         <identity value="rim" />
 425         <map value="N/A" />
 426       </mapping>
 427     </element>
 428     <element id="Extension.extension:requirements.value[x]">
 429       <path value="Extension.extension.value[x]" />
 430       <short value="Value of extension" />
 431       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
 432       <min value="1" />
 433       <max value="1" />
 434       <base>
 435         <path value="Extension.value[x]" />
 436         <min value="0" />
 437         <max value="1" />
 438       </base>
 439       <type>
 440         <code value="string" />
 441       </type>
 442       <constraint>
 443         <key value="ele-1" />
 444         <severity value="error" />
 445         <human value="All FHIR elements must have a @value or children" />
 446         <expression value="hasValue() or (children().count() > id.count())" />
 447         <xpath value="@value|f:*|h:div" />
 448         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 449       </constraint>
 450       <isModifier value="false" />
 451       <isSummary value="false" />
 452       <mapping>
 453         <identity value="rim" />
 454         <map value="N/A" />
 455       </mapping>
 456     </element>
 457     <element id="Extension.extension:severity">
 458       <path value="Extension.extension" />
 459       <sliceName value="severity" />
 460       <short value="error|warning" />
 461       <definition value="Indicates how serious violating the invariant is." />
 462       <min value="1" />
 463       <max value="1" />
 464       <base>
 465         <path value="Element.extension" />
 466         <min value="0" />
 467         <max value="*" />
 468       </base>
 469       <type>
 470         <code value="Extension" />
 471       </type>
 472       <constraint>
 473         <key value="ele-1" />
 474         <severity value="error" />
 475         <human value="All FHIR elements must have a @value or children" />
 476         <expression value="hasValue() or (children().count() > id.count())" />
 477         <xpath value="@value|f:*|h:div" />
 478         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 479       </constraint>
 480       <constraint>
 481         <key value="ext-1" />
 482         <severity value="error" />
 483         <human value="Must have either extensions or value[x], not both" />
 484         <expression value="extension.exists() != value.exists()" />
 485         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 486         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 487       </constraint>
 488       <isModifier value="false" />
 489       <isSummary value="false" />
 490     </element>
 491     <element id="Extension.extension:severity.id">
 492       <path value="Extension.extension.id" />
 493       <representation value="xmlAttr" />
 494       <short value="Unique id for inter-element referencing" />
 495       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 496       <min value="0" />
 497       <max value="1" />
 498       <base>
 499         <path value="Element.id" />
 500         <min value="0" />
 501         <max value="1" />
 502       </base>
 503       <type>
 504         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 505           <valueUrl value="string" />
 506         </extension>
 507         <code value="http://hl7.org/fhirpath/System.String" />
 508       </type>
 509       <isModifier value="false" />
 510       <isSummary value="false" />
 511       <mapping>
 512         <identity value="rim" />
 513         <map value="n/a" />
 514       </mapping>
 515     </element>
 516     <element id="Extension.extension:severity.extension">
 517       <path value="Extension.extension.extension" />
 518       <slicing>
 519         <discriminator>
 520           <type value="value" />
 521           <path value="url" />
 522         </discriminator>
 523         <description value="Extensions are always sliced by (at least) url" />
 524         <rules value="open" />
 525       </slicing>
 526       <short value="Extension" />
 527       <definition value="An Extension" />
 528       <min value="0" />
 529       <max value="0" />
 530       <base>
 531         <path value="Element.extension" />
 532         <min value="0" />
 533         <max value="*" />
 534       </base>
 535       <type>
 536         <code value="Extension" />
 537       </type>
 538       <constraint>
 539         <key value="ele-1" />
 540         <severity value="error" />
 541         <human value="All FHIR elements must have a @value or children" />
 542         <expression value="hasValue() or (children().count() > id.count())" />
 543         <xpath value="@value|f:*|h:div" />
 544         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 545       </constraint>
 546       <constraint>
 547         <key value="ext-1" />
 548         <severity value="error" />
 549         <human value="Must have either extensions or value[x], not both" />
 550         <expression value="extension.exists() != value.exists()" />
 551         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 552         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 553       </constraint>
 554       <isModifier value="false" />
 555       <isSummary value="false" />
 556     </element>
 557     <element id="Extension.extension:severity.url">
 558       <path value="Extension.extension.url" />
 559       <representation value="xmlAttr" />
 560       <short value="identifies the meaning of the extension" />
 561       <definition value="Source of the definition for the extension code - a logical name or a URL." />
 562       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
 563       <min value="1" />
 564       <max value="1" />
 565       <base>
 566         <path value="Extension.url" />
 567         <min value="1" />
 568         <max value="1" />
 569       </base>
 570       <type>
 571         <code value="uri" />
 572       </type>
 573       <fixedUri value="severity" />
 574       <isModifier value="false" />
 575       <isSummary value="false" />
 576       <mapping>
 577         <identity value="rim" />
 578         <map value="N/A" />
 579       </mapping>
 580     </element>
 581     <element id="Extension.extension:severity.value[x]">
 582       <path value="Extension.extension.value[x]" />
 583       <short value="Value of extension" />
 584       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
 585       <min value="1" />
 586       <max value="1" />
 587       <base>
 588         <path value="Extension.value[x]" />
 589         <min value="0" />
 590         <max value="1" />
 591       </base>
 592       <type>
 593         <code value="code" />
 594       </type>
 595       <constraint>
 596         <key value="ele-1" />
 597         <severity value="error" />
 598         <human value="All FHIR elements must have a @value or children" />
 599         <expression value="hasValue() or (children().count() > id.count())" />
 600         <xpath value="@value|f:*|h:div" />
 601         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 602       </constraint>
 603       <isModifier value="false" />
 604       <isSummary value="false" />
 605       <binding>
 606         <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
 607           <valueString value="ConstraintSeverity" />
 608         </extension>
 609         <strength value="required" />
 610         <description value="How important the invariant is." />
 611         <valueSet value="http://hl7.org/fhir/ValueSet/constraint-severity|4.0.1" />
 612       </binding>
 613       <mapping>
 614         <identity value="rim" />
 615         <map value="N/A" />
 616       </mapping>
 617     </element>
 618     <element id="Extension.extension:expression">
 619       <path value="Extension.extension" />
 620       <sliceName value="expression" />
 621       <short value="Formal rule" />
 622       <definition value="The FHIRPath expression of the rule for computable interpretation." />
 623       <min value="1" />
 624       <max value="1" />
 625       <base>
 626         <path value="Element.extension" />
 627         <min value="0" />
 628         <max value="*" />
 629       </base>
 630       <type>
 631         <code value="Extension" />
 632       </type>
 633       <constraint>
 634         <key value="ele-1" />
 635         <severity value="error" />
 636         <human value="All FHIR elements must have a @value or children" />
 637         <expression value="hasValue() or (children().count() > id.count())" />
 638         <xpath value="@value|f:*|h:div" />
 639         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 640       </constraint>
 641       <constraint>
 642         <key value="ext-1" />
 643         <severity value="error" />
 644         <human value="Must have either extensions or value[x], not both" />
 645         <expression value="extension.exists() != value.exists()" />
 646         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 647         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 648       </constraint>
 649       <isModifier value="false" />
 650       <isSummary value="false" />
 651     </element>
 652     <element id="Extension.extension:expression.id">
 653       <path value="Extension.extension.id" />
 654       <representation value="xmlAttr" />
 655       <short value="Unique id for inter-element referencing" />
 656       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 657       <min value="0" />
 658       <max value="1" />
 659       <base>
 660         <path value="Element.id" />
 661         <min value="0" />
 662         <max value="1" />
 663       </base>
 664       <type>
 665         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 666           <valueUrl value="string" />
 667         </extension>
 668         <code value="http://hl7.org/fhirpath/System.String" />
 669       </type>
 670       <isModifier value="false" />
 671       <isSummary value="false" />
 672       <mapping>
 673         <identity value="rim" />
 674         <map value="n/a" />
 675       </mapping>
 676     </element>
 677     <element id="Extension.extension:expression.extension">
 678       <path value="Extension.extension.extension" />
 679       <slicing>
 680         <discriminator>
 681           <type value="value" />
 682           <path value="url" />
 683         </discriminator>
 684         <description value="Extensions are always sliced by (at least) url" />
 685         <rules value="open" />
 686       </slicing>
 687       <short value="Extension" />
 688       <definition value="An Extension" />
 689       <min value="0" />
 690       <max value="0" />
 691       <base>
 692         <path value="Element.extension" />
 693         <min value="0" />
 694         <max value="*" />
 695       </base>
 696       <type>
 697         <code value="Extension" />
 698       </type>
 699       <constraint>
 700         <key value="ele-1" />
 701         <severity value="error" />
 702         <human value="All FHIR elements must have a @value or children" />
 703         <expression value="hasValue() or (children().count() > id.count())" />
 704         <xpath value="@value|f:*|h:div" />
 705         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 706       </constraint>
 707       <constraint>
 708         <key value="ext-1" />
 709         <severity value="error" />
 710         <human value="Must have either extensions or value[x], not both" />
 711         <expression value="extension.exists() != value.exists()" />
 712         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 713         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 714       </constraint>
 715       <isModifier value="false" />
 716       <isSummary value="false" />
 717     </element>
 718     <element id="Extension.extension:expression.url">
 719       <path value="Extension.extension.url" />
 720       <representation value="xmlAttr" />
 721       <short value="identifies the meaning of the extension" />
 722       <definition value="Source of the definition for the extension code - a logical name or a URL." />
 723       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
 724       <min value="1" />
 725       <max value="1" />
 726       <base>
 727         <path value="Extension.url" />
 728         <min value="1" />
 729         <max value="1" />
 730       </base>
 731       <type>
 732         <code value="uri" />
 733       </type>
 734       <fixedUri value="expression" />
 735       <isModifier value="false" />
 736       <isSummary value="false" />
 737       <mapping>
 738         <identity value="rim" />
 739         <map value="N/A" />
 740       </mapping>
 741     </element>
 742     <element id="Extension.extension:expression.value[x]">
 743       <path value="Extension.extension.value[x]" />
 744       <short value="Value of extension" />
 745       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
 746       <min value="1" />
 747       <max value="1" />
 748       <base>
 749         <path value="Extension.value[x]" />
 750         <min value="0" />
 751         <max value="1" />
 752       </base>
 753       <type>
 754         <code value="string" />
 755       </type>
 756       <constraint>
 757         <key value="ele-1" />
 758         <severity value="error" />
 759         <human value="All FHIR elements must have a @value or children" />
 760         <expression value="hasValue() or (children().count() > id.count())" />
 761         <xpath value="@value|f:*|h:div" />
 762         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 763       </constraint>
 764       <isModifier value="false" />
 765       <isSummary value="false" />
 766       <mapping>
 767         <identity value="rim" />
 768         <map value="N/A" />
 769       </mapping>
 770     </element>
 771     <element id="Extension.extension:human">
 772       <path value="Extension.extension" />
 773       <sliceName value="human" />
 774       <short value="Human-readable rule" />
 775       <definition value="A free text expression of the rule to display to the user if the rule is violated." />
 776       <min value="1" />
 777       <max value="1" />
 778       <base>
 779         <path value="Element.extension" />
 780         <min value="0" />
 781         <max value="*" />
 782       </base>
 783       <type>
 784         <code value="Extension" />
 785       </type>
 786       <constraint>
 787         <key value="ele-1" />
 788         <severity value="error" />
 789         <human value="All FHIR elements must have a @value or children" />
 790         <expression value="hasValue() or (children().count() > id.count())" />
 791         <xpath value="@value|f:*|h:div" />
 792         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 793       </constraint>
 794       <constraint>
 795         <key value="ext-1" />
 796         <severity value="error" />
 797         <human value="Must have either extensions or value[x], not both" />
 798         <expression value="extension.exists() != value.exists()" />
 799         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 800         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 801       </constraint>
 802       <isModifier value="false" />
 803       <isSummary value="false" />
 804     </element>
 805     <element id="Extension.extension:human.id">
 806       <path value="Extension.extension.id" />
 807       <representation value="xmlAttr" />
 808       <short value="Unique id for inter-element referencing" />
 809       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 810       <min value="0" />
 811       <max value="1" />
 812       <base>
 813         <path value="Element.id" />
 814         <min value="0" />
 815         <max value="1" />
 816       </base>
 817       <type>
 818         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 819           <valueUrl value="string" />
 820         </extension>
 821         <code value="http://hl7.org/fhirpath/System.String" />
 822       </type>
 823       <isModifier value="false" />
 824       <isSummary value="false" />
 825       <mapping>
 826         <identity value="rim" />
 827         <map value="n/a" />
 828       </mapping>
 829     </element>
 830     <element id="Extension.extension:human.extension">
 831       <path value="Extension.extension.extension" />
 832       <slicing>
 833         <discriminator>
 834           <type value="value" />
 835           <path value="url" />
 836         </discriminator>
 837         <description value="Extensions are always sliced by (at least) url" />
 838         <rules value="open" />
 839       </slicing>
 840       <short value="Extension" />
 841       <definition value="An Extension" />
 842       <min value="0" />
 843       <max value="0" />
 844       <base>
 845         <path value="Element.extension" />
 846         <min value="0" />
 847         <max value="*" />
 848       </base>
 849       <type>
 850         <code value="Extension" />
 851       </type>
 852       <constraint>
 853         <key value="ele-1" />
 854         <severity value="error" />
 855         <human value="All FHIR elements must have a @value or children" />
 856         <expression value="hasValue() or (children().count() > id.count())" />
 857         <xpath value="@value|f:*|h:div" />
 858         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 859       </constraint>
 860       <constraint>
 861         <key value="ext-1" />
 862         <severity value="error" />
 863         <human value="Must have either extensions or value[x], not both" />
 864         <expression value="extension.exists() != value.exists()" />
 865         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 866         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 867       </constraint>
 868       <isModifier value="false" />
 869       <isSummary value="false" />
 870     </element>
 871     <element id="Extension.extension:human.url">
 872       <path value="Extension.extension.url" />
 873       <representation value="xmlAttr" />
 874       <short value="identifies the meaning of the extension" />
 875       <definition value="Source of the definition for the extension code - a logical name or a URL." />
 876       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
 877       <min value="1" />
 878       <max value="1" />
 879       <base>
 880         <path value="Extension.url" />
 881         <min value="1" />
 882         <max value="1" />
 883       </base>
 884       <type>
 885         <code value="uri" />
 886       </type>
 887       <fixedUri value="human" />
 888       <isModifier value="false" />
 889       <isSummary value="false" />
 890       <mapping>
 891         <identity value="rim" />
 892         <map value="N/A" />
 893       </mapping>
 894     </element>
 895     <element id="Extension.extension:human.value[x]">
 896       <path value="Extension.extension.value[x]" />
 897       <short value="Value of extension" />
 898       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
 899       <min value="1" />
 900       <max value="1" />
 901       <base>
 902         <path value="Extension.value[x]" />
 903         <min value="0" />
 904         <max value="1" />
 905       </base>
 906       <type>
 907         <code value="string" />
 908       </type>
 909       <constraint>
 910         <key value="ele-1" />
 911         <severity value="error" />
 912         <human value="All FHIR elements must have a @value or children" />
 913         <expression value="hasValue() or (children().count() > id.count())" />
 914         <xpath value="@value|f:*|h:div" />
 915         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 916       </constraint>
 917       <isModifier value="false" />
 918       <isSummary value="false" />
 919       <mapping>
 920         <identity value="rim" />
 921         <map value="N/A" />
 922       </mapping>
 923     </element>
 924     <element id="Extension.extension:location">
 925       <path value="Extension.extension" />
 926       <sliceName value="location" />
 927       <short value="Relative path to elements" />
 928       <definition value="Relative paths to the questions this rule is enforced against." />
 929       <min value="0" />
 930       <max value="*" />
 931       <base>
 932         <path value="Element.extension" />
 933         <min value="0" />
 934         <max value="*" />
 935       </base>
 936       <type>
 937         <code value="Extension" />
 938       </type>
 939       <constraint>
 940         <key value="ele-1" />
 941         <severity value="error" />
 942         <human value="All FHIR elements must have a @value or children" />
 943         <expression value="hasValue() or (children().count() > id.count())" />
 944         <xpath value="@value|f:*|h:div" />
 945         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
 946       </constraint>
 947       <constraint>
 948         <key value="ext-1" />
 949         <severity value="error" />
 950         <human value="Must have either extensions or value[x], not both" />
 951         <expression value="extension.exists() != value.exists()" />
 952         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
 953         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
 954       </constraint>
 955       <isModifier value="false" />
 956       <isSummary value="false" />
 957     </element>
 958     <element id="Extension.extension:location.id">
 959       <path value="Extension.extension.id" />
 960       <representation value="xmlAttr" />
 961       <short value="Unique id for inter-element referencing" />
 962       <definition value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces." />
 963       <min value="0" />
 964       <max value="1" />
 965       <base>
 966         <path value="Element.id" />
 967         <min value="0" />
 968         <max value="1" />
 969       </base>
 970       <type>
 971         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
 972           <valueUrl value="string" />
 973         </extension>
 974         <code value="http://hl7.org/fhirpath/System.String" />
 975       </type>
 976       <isModifier value="false" />
 977       <isSummary value="false" />
 978       <mapping>
 979         <identity value="rim" />
 980         <map value="n/a" />
 981       </mapping>
 982     </element>
 983     <element id="Extension.extension:location.extension">
 984       <path value="Extension.extension.extension" />
 985       <slicing>
 986         <discriminator>
 987           <type value="value" />
 988           <path value="url" />
 989         </discriminator>
 990         <description value="Extensions are always sliced by (at least) url" />
 991         <rules value="open" />
 992       </slicing>
 993       <short value="Extension" />
 994       <definition value="An Extension" />
 995       <min value="0" />
 996       <max value="0" />
 997       <base>
 998         <path value="Element.extension" />
 999         <min value="0" />
1000         <max value="*" />
1001       </base>
1002       <type>
1003         <code value="Extension" />
1004       </type>
1005       <constraint>
1006         <key value="ele-1" />
1007         <severity value="error" />
1008         <human value="All FHIR elements must have a @value or children" />
1009         <expression value="hasValue() or (children().count() > id.count())" />
1010         <xpath value="@value|f:*|h:div" />
1011         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
1012       </constraint>
1013       <constraint>
1014         <key value="ext-1" />
1015         <severity value="error" />
1016         <human value="Must have either extensions or value[x], not both" />
1017         <expression value="extension.exists() != value.exists()" />
1018         <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")])" />
1019         <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
1020       </constraint>
1021       <isModifier value="false" />
1022       <isSummary value="false" />
1023     </element>
1024     <element id="Extension.extension:location.url">
1025       <path value="Extension.extension.url" />
1026       <representation value="xmlAttr" />
1027       <short value="identifies the meaning of the extension" />
1028       <definition value="Source of the definition for the extension code - a logical name or a URL." />
1029       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
1030       <min value="1" />
1031       <max value="1" />
1032       <base>
1033         <path value="Extension.url" />
1034         <min value="1" />
1035         <max value="1" />
1036       </base>
1037       <type>
1038         <code value="uri" />
1039       </type>
1040       <fixedUri value="location" />
1041       <isModifier value="false" />
1042       <isSummary value="false" />
1043       <mapping>
1044         <identity value="rim" />
1045         <map value="N/A" />
1046       </mapping>
1047     </element>
1048     <element id="Extension.extension:location.value[x]">
1049       <path value="Extension.extension.value[x]" />
1050       <short value="Value of extension" />
1051       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
1052       <min value="1" />
1053       <max value="1" />
1054       <base>
1055         <path value="Extension.value[x]" />
1056         <min value="0" />
1057         <max value="1" />
1058       </base>
1059       <type>
1060         <code value="string" />
1061       </type>
1062       <constraint>
1063         <key value="ele-1" />
1064         <severity value="error" />
1065         <human value="All FHIR elements must have a @value or children" />
1066         <expression value="hasValue() or (children().count() > id.count())" />
1067         <xpath value="@value|f:*|h:div" />
1068         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
1069       </constraint>
1070       <isModifier value="false" />
1071       <isSummary value="false" />
1072       <mapping>
1073         <identity value="rim" />
1074         <map value="N/A" />
1075       </mapping>
1076     </element>
1077     <element id="Extension.url">
1078       <path value="Extension.url" />
1079       <representation value="xmlAttr" />
1080       <short value="identifies the meaning of the extension" />
1081       <definition value="Source of the definition for the extension code - a logical name or a URL." />
1082       <comment value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension." />
1083       <min value="1" />
1084       <max value="1" />
1085       <base>
1086         <path value="Extension.url" />
1087         <min value="1" />
1088         <max value="1" />
1089       </base>
1090       <type>
1091         <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
1092           <valueUrl value="uri" />
1093         </extension>
1094         <code value="http://hl7.org/fhirpath/System.String" />
1095       </type>
1096       <fixedUri value="http://hl7.org/fhir/StructureDefinition/questionnaire-constraint" />
1097       <isModifier value="false" />
1098       <isSummary value="false" />
1099       <mapping>
1100         <identity value="rim" />
1101         <map value="N/A" />
1102       </mapping>
1103     </element>
1104     <element id="Extension.value[x]">
1105       <path value="Extension.value[x]" />
1106       <short value="Value of extension" />
1107       <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/extensibility.html) for a list)." />
1108       <min value="0" />
1109       <max value="0" />
1110       <base>
1111         <path value="Extension.value[x]" />
1112         <min value="0" />
1113         <max value="1" />
1114       </base>
1115       <type>
1116         <code value="base64Binary" />
1117       </type>
1118       <type>
1119         <code value="boolean" />
1120       </type>
1121       <type>
1122         <code value="canonical" />
1123       </type>
1124       <type>
1125         <code value="code" />
1126       </type>
1127       <type>
1128         <code value="date" />
1129       </type>
1130       <type>
1131         <code value="dateTime" />
1132       </type>
1133       <type>
1134         <code value="decimal" />
1135       </type>
1136       <type>
1137         <code value="id" />
1138       </type>
1139       <type>
1140         <code value="instant" />
1141       </type>
1142       <type>
1143         <code value="integer" />
1144       </type>
1145       <type>
1146         <code value="markdown" />
1147       </type>
1148       <type>
1149         <code value="oid" />
1150       </type>
1151       <type>
1152         <code value="positiveInt" />
1153       </type>
1154       <type>
1155         <code value="string" />
1156       </type>
1157       <type>
1158         <code value="time" />
1159       </type>
1160       <type>
1161         <code value="unsignedInt" />
1162       </type>
1163       <type>
1164         <code value="uri" />
1165       </type>
1166       <type>
1167         <code value="url" />
1168       </type>
1169       <type>
1170         <code value="uuid" />
1171       </type>
1172       <type>
1173         <code value="Address" />
1174       </type>
1175       <type>
1176         <code value="Age" />
1177       </type>
1178       <type>
1179         <code value="Annotation" />
1180       </type>
1181       <type>
1182         <code value="Attachment" />
1183       </type>
1184       <type>
1185         <code value="CodeableConcept" />
1186       </type>
1187       <type>
1188         <code value="Coding" />
1189       </type>
1190       <type>
1191         <code value="ContactPoint" />
1192       </type>
1193       <type>
1194         <code value="Count" />
1195       </type>
1196       <type>
1197         <code value="Distance" />
1198       </type>
1199       <type>
1200         <code value="Duration" />
1201       </type>
1202       <type>
1203         <code value="HumanName" />
1204       </type>
1205       <type>
1206         <code value="Identifier" />
1207       </type>
1208       <type>
1209         <code value="Money" />
1210       </type>
1211       <type>
1212         <code value="Period" />
1213       </type>
1214       <type>
1215         <code value="Quantity" />
1216       </type>
1217       <type>
1218         <code value="Range" />
1219       </type>
1220       <type>
1221         <code value="Ratio" />
1222       </type>
1223       <type>
1224         <code value="Reference" />
1225       </type>
1226       <type>
1227         <code value="SampledData" />
1228       </type>
1229       <type>
1230         <code value="Signature" />
1231       </type>
1232       <type>
1233         <code value="Timing" />
1234       </type>
1235       <type>
1236         <code value="ContactDetail" />
1237       </type>
1238       <type>
1239         <code value="Contributor" />
1240       </type>
1241       <type>
1242         <code value="DataRequirement" />
1243       </type>
1244       <type>
1245         <code value="Expression" />
1246       </type>
1247       <type>
1248         <code value="ParameterDefinition" />
1249       </type>
1250       <type>
1251         <code value="RelatedArtifact" />
1252       </type>
1253       <type>
1254         <code value="TriggerDefinition" />
1255       </type>
1256       <type>
1257         <code value="UsageContext" />
1258       </type>
1259       <type>
1260         <code value="Dosage" />
1261       </type>
1262       <type>
1263         <code value="Meta" />
1264       </type>
1265       <constraint>
1266         <key value="ele-1" />
1267         <severity value="error" />
1268         <human value="All FHIR elements must have a @value or children" />
1269         <expression value="hasValue() or (children().count() > id.count())" />
1270         <xpath value="@value|f:*|h:div" />
1271         <source value="http://hl7.org/fhir/StructureDefinition/Element" />
1272       </constraint>
1273       <isModifier value="false" />
1274       <isSummary value="false" />
1275       <mapping>
1276         <identity value="rim" />
1277         <map value="N/A" />
1278       </mapping>
1279     </element>
1280   </snapshot>
1281   <differential>
1282     <element id="Extension">
1283       <path value="Extension" />
1284       <short value="Constraint" />
1285       <definition value="An invariant that must be satisfied before responses to the questionnaire can be considered "complete"." />
1286       <comment value="This maps to the ElementDefinition.constraint element." />
1287       <min value="0" />
1288       <max value="*" />
1289     </element>
1290     <element id="Extension.extension:key">
1291       <path value="Extension.extension" />
1292       <sliceName value="key" />
1293       <short value="Unique identifier" />
1294       <definition value="Unique id for the constraint within the questionnaire." />
1295       <min value="1" />
1296       <max value="1" />
1297       <type>
1298         <code value="Extension" />
1299       </type>
1300     </element>
1301     <element id="Extension.extension:key.extension">
1302       <path value="Extension.extension.extension" />
1303       <max value="0" />
1304     </element>
1305     <element id="Extension.extension:key.url">
1306       <path value="Extension.extension.url" />
1307       <type>
1308         <code value="uri" />
1309       </type>
1310       <fixedUri value="key" />
1311     </element>
1312     <element id="Extension.extension:key.value[x]">
1313       <path value="Extension.extension.value[x]" />
1314       <min value="1" />
1315       <type>
1316         <code value="id" />
1317       </type>
1318     </element>
1319     <element id="Extension.extension:requirements">
1320       <path value="Extension.extension" />
1321       <sliceName value="requirements" />
1322       <short value="Why needed" />
1323       <definition value="An explanation of why this extension is required (for documentation purposes)." />
1324       <min value="0" />
1325       <max value="1" />
1326       <type>
1327         <code value="Extension" />
1328       </type>
1329     </element>
1330     <element id="Extension.extension:requirements.extension">
1331       <path value="Extension.extension.extension" />
1332       <max value="0" />
1333     </element>
1334     <element id="Extension.extension:requirements.url">
1335       <path value="Extension.extension.url" />
1336       <type>
1337         <code value="uri" />
1338       </type>
1339       <fixedUri value="requirements" />
1340     </element>
1341     <element id="Extension.extension:requirements.value[x]">
1342       <path value="Extension.extension.value[x]" />
1343       <min value="1" />
1344       <type>
1345         <code value="string" />
1346       </type>
1347     </element>
1348     <element id="Extension.extension:severity">
1349       <path value="Extension.extension" />
1350       <sliceName value="severity" />
1351       <short value="error|warning" />
1352       <definition value="Indicates how serious violating the invariant is." />
1353       <min value="1" />
1354       <max value="1" />
1355       <type>
1356         <code value="Extension" />
1357       </type>
1358     </element>
1359     <element id="Extension.extension:severity.extension">
1360       <path value="Extension.extension.extension" />
1361       <max value="0" />
1362     </element>
1363     <element id="Extension.extension:severity.url">
1364       <path value="Extension.extension.url" />
1365       <type>
1366         <code value="uri" />
1367       </type>
1368       <fixedUri value="severity" />
1369     </element>
1370     <element id="Extension.extension:severity.value[x]">
1371       <path value="Extension.extension.value[x]" />
1372       <min value="1" />
1373       <type>
1374         <code value="code" />
1375       </type>
1376       <binding>
1377         <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
1378           <valueString value="ConstraintSeverity" />
1379         </extension>
1380         <strength value="required" />
1381         <description value="How important the invariant is." />
1382         <valueSet value="http://hl7.org/fhir/ValueSet/constraint-severity|4.0.1" />
1383       </binding>
1384     </element>
1385     <element id="Extension.extension:expression">
1386       <path value="Extension.extension" />
1387       <sliceName value="expression" />
1388       <short value="Formal rule" />
1389       <definition value="The FHIRPath expression of the rule for computable interpretation." />
1390       <min value="1" />
1391       <max value="1" />
1392       <type>
1393         <code value="Extension" />
1394       </type>
1395     </element>
1396     <element id="Extension.extension:expression.extension">
1397       <path value="Extension.extension.extension" />
1398       <max value="0" />
1399     </element>
1400     <element id="Extension.extension:expression.url">
1401       <path value="Extension.extension.url" />
1402       <type>
1403         <code value="uri" />
1404       </type>
1405       <fixedUri value="expression" />
1406     </element>
1407     <element id="Extension.extension:expression.value[x]">
1408       <path value="Extension.extension.value[x]" />
1409       <min value="1" />
1410       <type>
1411         <code value="string" />
1412       </type>
1413     </element>
1414     <element id="Extension.extension:human">
1415       <path value="Extension.extension" />
1416       <sliceName value="human" />
1417       <short value="Human-readable rule" />
1418       <definition value="A free text expression of the rule to display to the user if the rule is violated." />
1419       <min value="1" />
1420       <max value="1" />
1421       <type>
1422         <code value="Extension" />
1423       </type>
1424     </element>
1425     <element id="Extension.extension:human.extension">
1426       <path value="Extension.extension.extension" />
1427       <max value="0" />
1428     </element>
1429     <element id="Extension.extension:human.url">
1430       <path value="Extension.extension.url" />
1431       <type>
1432         <code value="uri" />
1433       </type>
1434       <fixedUri value="human" />
1435     </element>
1436     <element id="Extension.extension:human.value[x]">
1437       <path value="Extension.extension.value[x]" />
1438       <min value="1" />
1439       <type>
1440         <code value="string" />
1441       </type>
1442     </element>
1443     <element id="Extension.extension:location">
1444       <path value="Extension.extension" />
1445       <sliceName value="location" />
1446       <short value="Relative path to elements" />
1447       <definition value="Relative paths to the questions this rule is enforced against." />
1448       <min value="0" />
1449       <max value="*" />
1450       <type>
1451         <code value="Extension" />
1452       </type>
1453     </element>
1454     <element id="Extension.extension:location.extension">
1455       <path value="Extension.extension.extension" />
1456       <max value="0" />
1457     </element>
1458     <element id="Extension.extension:location.url">
1459       <path value="Extension.extension.url" />
1460       <type>
1461         <code value="uri" />
1462       </type>
1463       <fixedUri value="location" />
1464     </element>
1465     <element id="Extension.extension:location.value[x]">
1466       <path value="Extension.extension.value[x]" />
1467       <min value="1" />
1468       <type>
1469         <code value="string" />
1470       </type>
1471     </element>
1472     <element id="Extension.url">
1473       <path value="Extension.url" />
1474       <fixedUri value="http://hl7.org/fhir/StructureDefinition/questionnaire-constraint" />
1475     </element>
1476     <element id="Extension.value[x]">
1477       <path value="Extension.value[x]" />
1478       <min value="0" />
1479       <max value="0" />
1480     </element>
1481   </differential>
1482 </StructureDefinition>